Meant to mention - Mango is NOT connected to the internet…and that’ the way it needs to be, as we’re trying to setup a Mobile LAN for Primary Care clinics that need to operate in remote areas that won’t have an internet connection…
Hopefully someone smarter will chime in but it might be helpful to know more about the environment. I see on your website that this is running on windows 10… Does windows have a native webserver or is it on apache or some other server? I presume to be considered secure enough to store sensitive info, a windows computer has had some major locking down done. Is there maybe a firewall or something local blocking access?
My suspicion would be to investigate the host machine rather than the router. I’ve set up things like this and never had to fiddle with the router to get basic functionality.